Talking with people around here that have iPhones. Those that have the 5s are not looking to upgrade yet. Those with anything slower/older than the 5s are all going to get the regular 6. Don't know a single person interested in the 6+ yet that is a current iphone user.
I'm moving from a 5 to a 6+.
There isn't really an upgrade from the 5s to the 6 or 6+ at all right now except for the NFC which isn't a big deal to most of the people around here. There isn't many terminals that accept NFC payments yet where I like. Walgreens, and a few vending machines are the only things I have found with working NFC consoles. There are a few grocery stores and other places that have the emblem for NFC payments, but it doesn't actually work at those terminals yet.
There is a lot of buzz in the payment industry over Apple Pay. This has the potential to be HUGE for Apple. A lot of existing NFC enabled terminals will support Apple Pay. That's one of the secrets to the many retailers supporting Apple Pay...they already got NFC terminals. Ars Technica has a great article regarding Apple Pay and how timing and the maturation of NFC has Apple in a position to reap the benefits of the perfect storm. Basically, PCI Compliance 3.0 and EMV requirements will force many merchants to upgrade equipment, which will almost certainly be Apple Pay compatible.
Without seeing a review yet, the camera looks like a very nice upgrade on the 6+.
Much better battery life on the 6+ is a huge bonus for me. I do a lot of support on a mobile device and the larger screen coupled with better battery life means easier support for our clients using remote access software.
So unless you really want a bigger screen, which most current iphone users I personally know don't, those with the 5s are really disappointed and aren't upgrading. Least that is what feedback I've received. They are waiting for the 6s or something later for an actual upgrade.
Those with anything older than the 5s are on the pre-order bandwagon though for the regular 6.
There's a ton of pent up demand for a larger iPhone. I know of a few Note3 users upgrading to an iPhone 6+. I do agree that for those with a 5S who don't like the larger screen size, the upgrade is not as great.
As others have said, a lot of the features of the 6/6+ are already present on Android phones but sometimes good implementation beats out early implementation.
I will however, disagree with those who blindly say that Apple never innovates or only copies. Apple is very smart with what they implement first (higher res display, 64bit support, etc.) but I do feel that lately, they've been handcuffed by their success and slow to move forward in creative ways. As much of an egomaniac and control freak Steve Jobs was, he recognized what would be the "next big thing" for Apple. Tim Cooks is a good CEO, but he doesn't have the creative flair that Jobs had. And to be honest, I don't think Jony Ive has it either. Ive's designs were tempered by Jobs' hardass attitude.